I took three bullets for Princess Anne

In March 1974, Jim Beaton, a royalty protection officer, helped prevent the kidnapping of Princess Anne as she was returning to Buckingham Palace in a chauffeur-driven limousine.

A white car swerved in front of the limousine as it drove along the Mall. A man, Ian Ball, jumped out and went round to the side where Princess Anne was sitting.

Jim Beaton attempted to intervene but was shot. He fired his weapon but missed on account of his injuries and then the gun jammed. Another attempt to knock over Ball failed and Beaton was shot a third time.

Ball was later grappled to the ground by a policeman. In all, four people were wounded.

Ball, 26 at the time, was prosecuted for the attempted murder of Jim Beaton and various other offences.

His attempt to kidnap the princess remains the closest anyone has come to abducting a member of the Royal Family.

Witness is a World Service radio programme of the stories of our times told by the people who were there.